An Efficient Autonomous Path Proxy Re-encryption Without Pairing for Cloud-Assisted mHealth

We propose the first construction of an efficient AP-PRE scheme without pairing for data confidentiality in the cloud-assisted Mobile Health (mHealth) system. In our scheme, the user can outsource his encrypted Personal Health Information (PHI) to the Cloud Service Provider (CSP) and share it with a list of doctors ordered in priority, where he has complete control over the transformation of the ciphertext. Based on the Modified Computational Diffie-Hellman (M-CDH) assumption, we prove the chosen-ciphertext security for our proposed scheme in the Random Oracle (RO) model. We demonstrate that our proposed AP-PRE scheme is highly efficient by comparing it with previous AP-PRE schemes based on bilinear pairing.